Brush holder apparatus and system

ABSTRACT

A brush holder apparatus includes a stationary support member having at least one groove and a fork electrical connector. A brush retainment member has a brush restraint apparatus having a plunger brush restraint configured to restrain a brush from sliding within the brush retainment member by pressing it against the brush retainment member. The brush retainment member has at least one rail configured to slide along the at least one groove, and a knife electrical connector configured to mate with the fork electrical connector. The brush retainment member is configured to be releasably affixed to the stationary support member. The stationary support member is configured for electrical connection to a collector mount, and the brush retainment member is configured to retain at least one brush.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to a brush holder apparatusand system. Specifically, the subject matter disclosed herein relates toa brush holder apparatus and system configured to conduct electricalcurrent between a brush and a rotating element of a dynamoelectricmachine (e.g., an electrical generator, electrical motor, etc.) and/oranother rotating machine (e.g., a rotating crane).

Conventional dynamoelectric machines include a rotor having windingsthat conduct electrical current during operation of the machine. As therotor rotates, rotating elements are used to conduct current to therotor windings from a source external to the rotor. The rotatingelements such as collector rings or commutators make contact withbrushes to conduct the current. As the brushes are stationary withrespect to the rotating elements, the brushes, which are made of carbon,wear due to friction and need periodic replacement.

Due to a desire to decrease downtime during operation of thedynamoelectric machine, brushes are sometimes replaced during operationof the dynamoelectric machine. In order to replace brushes safely, anoperator uses a single hand (in order to avoid conducting electricalcurrent through the operator's body). Conventional brush holders can beheavy and unwieldy, making brush replacement both difficult anddangerous.

BRIEF DESCRIPTION OF THE INVENTION

According to an aspect of the invention, a brush holder apparatusincludes a stationary support member having at least one groove and afork electrical connector. A brush retainment member has a brushrestraint apparatus having a plunger brush restraint configured torestrain a brush from sliding within the brush retainment member bypressing it against the brush retainment member. The brush retainmentmember has at least one rail configured to slide along the at least onegroove, and a knife electrical connector configured to mate with thefork electrical connector. The brush retainment member is configured tobe releasably affixed to the stationary support member. The stationarysupport member is configured for electrical connection to a collectormount, and the brush retainment member is configured to retain at leastone brush.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of this invention will be more readilyunderstood from the following detailed description of the variousaspects of the invention taken in conjunction with the accompanyingdrawings that depict various embodiments of the invention, in which:

FIG. 1 illustrates a partial perspective view of a single brush holderinstalled on a collector horseshoe, according to an aspect of thepresent invention.

FIG. 2 illustrates a perspective view of the stationary support member,according to an aspect of the present invention.

FIG. 3 illustrates a perspective rear view of the stationary supportmember 102 as shown in FIG. 2, according to an aspect of the presentinvention.

FIG. 4 illustrates a perspective front view of the brush retainmentmember, according to an aspect of the present invention.

FIG. 5 illustrates a perspective rear view of the brush retainmentmember, according to an aspect of the present invention.

FIG. 6 illustrates a bottom view of the brush retainment member and thecam members used to retain the brushes, according to an aspect of thepresent invention.

FIG. 7 illustrates a perspective view of a stationary support member,according to an aspect of the present invention.

FIG. 8 illustrates a schematic view of a plunger brush restraint thatmay be used with the brush holder, according to an aspect of the presentinvention.

FIG. 9 illustrates a schematic view of a plunger brush restraint thatmay be used with the brush holder, according to an aspect of the presentinvention.

FIG. 10 illustrates a perspective view of a brush holder incorporatingan RFID tag for sensing brush wear, according to an aspect of thepresent invention.

FIG. 11 illustrates a perspective view of the RFID tag of FIG. 10,according to an aspect of the present invention.

FIG. 12 illustrates a simplified schematic view of a system in adynamoelectric machine, according to an aspect of the present invention.

FIG. 13 illustrates a simplified side view of the cam in two positions,according to an aspect of the present invention.

It is noted that the drawings of the invention are not necessarily toscale. The drawings are intended to depict only typical aspects of theinvention, and therefore should not be considered as limiting the scopeof the invention. In the drawings, like numbering represents likeelements between the drawings.

DETAILED DESCRIPTION OF THE INVENTION

Aspects of the invention provide for a brush holder assembly (orapparatus) configured to conduct electrical current between a brush anda rotating element of a dynamoelectric machine (e.g., an electricalgenerator, electrical motor, etc.) and/or another rotating machine(e.g., a rotating crane). In particular, aspects of the inventionprovide for a brush holder assembly that may aid an operator in safelyremoving/replacing brushes in a dynamoelectric machine and/or anotherrotating machine.

As described herein, conventional dynamoelectric machines include arotor having windings that conduct electrical current during operationof the machine. As the rotor rotates, rotating elements are used toconduct current to the rotor windings from a source external to therotor. The rotating elements such as collector rings or commutators makecontact with brushes to conduct the current. As the brushes arestationary with respect to the rotating elements, the brushes, which aremade of carbon, wear due to friction and need periodic replacement.

Due to a desire to decrease downtime during operation of thedynamoelectric machine, brushes are sometimes replaced during operationof the dynamoelectric machine. In order to replace brushes safely, anoperator uses a single hand (in order to avoid conducting electricalcurrent through the operator's body). Conventional brush holders can beheavy and unwieldy, making brush replacement both difficult anddangerous.

In contrast to conventional brush holders, aspects of the inventioninclude a brush holder apparatus for a dynamoelectric machine includinga rotating cam brush retainer. This cam-style brush retainer may allowfor efficient and safe installation and/or removal of brushes fromdynamoelectric machines.

FIG. 1 illustrates a partial perspective view of a single brush holderinstalled on a collector horseshoe, according to an aspect of thepresent invention. A brush mount or collector horseshoe 110 is mountedover a collector ring 120. The collector ring rotates along with therotor (not shown). A plurality of brushes and corresponding brushholders are attached to the collector horseshoe and are distributed atleast partially around the collector ring. In this example, only asingle brush holder apparatus 100 is shown attached to the collectorhorseshoe 110. The brush holder apparatus 100 may be bolted or screwedto the collector horseshoe, or any other suitable method may beemployed. The brush holder apparatus 100 includes a stationary supportmember 102 and a brush retainment member 104. The stationary supportmember 102 is configured for electrical connection to the collectormount (i.e., collector horseshoe 110), for example, by being fabricatedof a conductive material or including a conductive material. The brushretainment member 104 is configured to retain the brush (containedtherein) at least in the axial and circumferential directions.

FIG. 2 illustrates a perspective view of the stationary support member102, according to an aspect of the present invention. The stationarysupport member 102 includes at least one groove 210 (two are shown inFIG. 2) and a fork electrical connector 220. The fork electricalconnector 220 may extend to one or both sides of the stationary supportmember, or alternatively the fork electrical connector may only becentrally located without extending to the sides of the stationarysupport member. A tapered slot 230 is located in an upper portion of thestationary support member 102, and the slot 230 is configured forcooperation with a locking pin 450 on the brush retainment member. Thelocking pin could also be replaced by a bar or latch or protrusion ordisc with a ramped surface. The tapered nature of slot 230 acts to forcethe brush retainment member down into the connector 220 as the lockingpin 450 is rotated. A bar 240 may be located near a bottom end of thestationary support member 102, and this bar is configured to engage andrestrain a cam on the brush retainment member 104. The bar 240 alsoserves to limit the distance the brush retainment member 104 can beinserted into the stationary support member 102. The brush retainmentmember 104 is fixed in position relative to the stationary supportmember 102 between the locking pin 450 at top and the bar 240 at thebottom. The bar 240 is fully contained within the profile of thestationary support member 102 and does not protrude past that profile. Aplurality of holes 250 are provided and are configured to facilitateattachment of the stationary support member 102 to the collector mount(or collector horseshoe 110). The holes 250 may be internally threadedfor use with mechanical fasteners, such as bolts or screws. In addition,the holes 250 may be provided on both sides of the stationary supportmember 102 so that they are configured to attach a plurality ofstationary support members together in a stacked or side-by-sidearrangement. This may be desired when multiple brushes are stackedside-by-side. For example, 3, 4, 5, 6, 7 or more brushes may be arrangedat one circumferential location on collector horseshoe 110. A conductivespacer plate (or bar) 260 may be located on one or more sides of thestationary support member 102. The conductive spacer plate/bar 260 isconfigured to provide electrical conductivity with the collector mount(collector horseshoe 110) and/or a second stationary support member(e.g., connected to the side of the first stationary support member).

FIG. 3 illustrates a perspective rear view of the stationary supportmember 102 as shown in FIG. 2, according to an aspect of the presentinvention. The conductive bar 260 passes through a portion of thestationary support member's main body 103, and is configured to provideelectrical conductivity with the collector mount 110 and the forkelectrical connector 220. This arrangement enables the stationarysupport 102 to be fully electrically insulated and the current to passfrom the horseshoe 110 to the fork 220 through the conductive bar 260.The holes 250 to mount to the horseshoe 110 are formed in conductive bar260. In alternative embodiments, the conductive bar 260 may belengthened so that multiple stationary supports 102 could be attached tothe same (longer) conductive bar 260. The conductive bar 260 may beattached to the stationary support 102 and the fork 220 via bolts thatrun up through the bottom of the stationary support through theconductive bar 260 and into either the electrical fork 220 and/or one ormore tabs/bosses 270. In this example, one tab/boss 270 is shown on eachside of the electrical fork 220. The fork electrical connector 220 mayalso be formed integrally with the conductive bar 260.

The stationary support member 102 may be configured to accept one, two(as shown), three, or more brush retainment members. A preferred versionwould be a stationary support member that accepts one or two brushes,and multiple stationary support members and can be arranged side-by-sidefor applications needing a specific number of brushes at a givencircumferential location on the collector horseshoe. The stationarysupport member 102 and/or the brush retainment member may be formedsubstantially (or comprised) of aluminum, an aluminum alloy, stainlesssteel or any other suitable electrically conductive or electricallynon-conductive material as desired in the specific application. As onenon-limiting example only, the stationary support member 102 and thebrush retainment member 104 may be formed substantially (or comprised)of a passivated or anodized aluminum, or a passivated or anodizedaluminum alloy. This material will give good strength while providing anelectrically insulating or electrically semi-insulating material. It isdesired to minimize current flow through the brush holder body and focusthe current flow through the brushes and electrical path of the brushholder designed for this current flow. In addition, it would bedesirable to minimize (or even block) any current flow to portions thatmay be grasped by a technician during insertion or removal. Also, it isdesirable to avoid the possibility of current arcing directly from thecollector ring 120 to the brush retainment member 104 or to thestationary support member 102 when a brush 432 is worn out and no longerable to be part of the path for the current. At least a portion of asurface of at least one of the stationary support member and the brushretainment member is configured to be substantially electricallyinsulating. For example, the handle of the brush retainment membershould be substantially electrically insulating to protect a technicianduring insertion or removal of the brush holder on an operating machine.Alternatively, the stationary support member and the brush retainmentmember may be formed substantially (or comprised) of a powder coated orpainted aluminum or a powder coated or painted aluminum alloy or apowder coated metallic or non-metallic material or a ceramic coatedmetallic or ceramic coated non-metallic material.

FIG. 4 illustrates a perspective front view of the brush retainmentmember 104, according to an aspect of the present invention. FIG. 5illustrates a perspective rear view of the brush retainment member 104,according to an aspect of the present invention. The brush retainmentmember 104 is configured to be releasably affixed to the stationarysupport member 102. At least one rail 410 is configured to slide alonggroove 210. In the example shown the brush retainment member 104includes two rails 410, one on each side of the brush retainment member.A knife electrical connector 420, configured to mate with the forkelectrical connector 220, is located on the rear of the brush retainmentmember 104. A brush retaining box 430 retains one or more brushes 432 inthe axial and circumferential directions. In the example shown, box 430retains two brushes 432. The brushes 432 are biased radially downward bybrush springs 434. Apertures 431 form windows in the box 430 and allowthe brushes 432 to be seen and visually monitored for wear.

The brush retainment member 104 includes a handle assembly 440 thatincludes an electrically insulating handle 442 and an electricallyinsulating guard 444 or shield that is located between the handle 442and the brush connector leads 436. The brush connector leads 436 carryhigh voltage and current while the dynamoelectric machine is operating,so these present a hazard to be avoided. The electrically insulatinghandle 442 and guard 444 will prevent a technician's hand from cominginto contact with the energized brush connector leads 436. The handle442 and guard 444 may be comprised of plastic, rubber, epoxy/fiberglasslaminate, fiberglass, or any other suitable electrically insulatingmaterial.

The locking pin 450 is configured for cooperation with the tapered slot230 in the stationary support member 102. The handle assembly canrotate, and as it rotates the locking pin 450 can be rotated into, orout of, the tapered slot 230. The views of FIGS. 4 and 5 show thelocking pin 450 and handle 442 oriented in the locked position. In thislocked position the locking pin 450 is fully inserted into the slot 230and the tapered surface drives the locking pin radially downward. Inother words, the handle assembly 440 is configured to be rotated about90 degrees, a 0 degree position configured so that the locking pin 450is disengaged from the tapered slot 230 so that the brush retainmentmember 104 may be removed from the stationary support member 102. A 90degree position (as shown in FIGS. 4 and 5) is configured so that thelocking pin 450 is engaged in the tapered slot 230 so that the brushretainment member 104 is fully locked into operating condition on thestationary support member 102. By having the handle 442 orientedparallel to the locking pin 450 and having the locking pin 450 extendthrough the tapered slot 230, the operator can easily see that the brushretainment member 104 is fully inserted and locked in place within thestationary support 102.

A spring assembly 460 is housed within the handle assembly 440, and thespring assembly is mechanically connected to the brush terminalcompression plate 470 (two of which are shown). The brush terminalcompression plate may be one piece that extends through the shaft of thehandle, but it could also be fabricated from two pieces. The brushes 432are connected to the brush terminals 438 via brush connector leads (orpigtails) 436. The brush terminals 438 are electrically connected to theknife electrical connector 420. For example, the knife electricalconnector includes an electrically conductive base member that extendsunder each brush terminal 438, thereby making an electrically conductivepath. The spring assembly 460 biases the compression plates 470 downwardand this downward pressure retains the brush terminals in place andagainst the base member of the knife electrical connector 420. This isparticularly advantageous when the brush retainment member 104 is beinginserted (or removed from) the stationary support member 102. It isadvised to use only one hand when manually inserting or removing thebrushes, and the spring assembly ensures that a second hand is notrequired to keep the brush terminals 438 in place. Once the brushretainment member 104 is fully inserted into the stationary supportmember, the handle 442 is rotated 90 degrees (into a locked position)and the tapered slot 230 forces the locking pin 450 (as well as brushretainment member 104) radially downward applying additional force ontothe brush terminals 438. An advantage of this design is that the brushretainment member 104 is configured to clamp a brush terminal 438between a terminal compression plate 470 and an opposing surface of thebrush retainment member (i.e., the electrically conductive base memberof knife electrical connector 420), so that the brush terminal isengaged or released without the use of any tools. All that is requiredis manual placement of the respective parts by hand. Minimizing oreliminating the use of specific tools can greatly simplify and increasethe safety of working around dynamoelectric machines, especially whenthey are operating and energized.

As illustrated, the brush box 430 is configured to hold two brushes 432.However, the box 430 can be configured to hold one brush 432 (byreducing the width of the box) or three or more brushes (by increasingthe width of the box and providing additional individual brushapertures). The brush terminal 438 includes an upward bend located at adistal end thereof. This bend helps to keep the brush terminal in placeunder the compression plate 470. The bend could also be replaced by arib or a rail. A hole or notch could also be provided in the brushterminal that cooperates with a complementary feature on the terminalcompression plate 470 or the electrically conductive base member ofknife electrical connector 420. For example, if the brush terminal 438included a hole in the center thereof, the compression plate 470 couldhave a complementary pin located to engage the hole of the brushterminal. This complementary feature on the brush retainment memberfacilitates securing the brush terminal to the brush retainment member.The inverse could also be used, with the brush terminal having acomplementary pin and the compression plate having the hole. With thisarrangement, the brush retainment member 104 is configured toelectrically and mechanically connect the knife electrical connector 220to the brush terminal 438, while both the knife electrical connector 220and the brush terminal 438 are electrically insulated from handle 442.

As the brush 432 wears down due to frictional contact with the rotorcollector ring 120, the brush spring 434 will keep the eroding surfaceof the brush 432 in contact with the rotor collector ring 120. The brushspring 434 is configured to press the brush 432 radially downward andagainst the collector ring 120, because the spring 434 is designed withtension to re-coil itself. In this manner, the coil at the top of thespring 434 wants to re-tighten or coil downward, thereby applying aradially downward force to brush 432. The brush spring 434 includes abent support plate 435 immediately behind and above the coiled spring434. The spring 434 may be riveted to the bottom of the bent supportplate 435. The bent support plate 435 may also include an angled tabconfigured for insertion into a complementary recess in the brushretainment member 104. The brush spring 434 and bent support plate 435are flexible to allow the angled tab to be moved into the complementaryrecess for insertion of the brush spring, and out of the complementaryrecess for removal of the brush spring. The brush spring 434 and bentsupport plate 435 are also configured to be located in-line with the cammember 610 configured for restraining the brush 432 against the brushretainment member or box 430. This in-line arrangement is aligned sothat any potential binding is reduced or eliminated and smooth operationis permitted between the spring 434, brush 432 and cam members 610.

FIG. 6 illustrates a bottom view of the brush retainment member 104 andthe cam members 610 used to retain the brushes 432, according to anaspect of the present invention. A cam member 610 is operably connectedto the shaft 620 near a bottom of the brush retainment member 104. Thecam member 610 is configured to retain the brush 432 against the brushretainment member or box 430 until the brush retainment member 104 isfully inserted in the stationary support member 102. The cam member 610is constant-angle cam shaped and is mounted with a spring 612 (e.g., atorsional spring) to shaft 620. The constant-angle cam shape isconsistent with logarithmic spiral geometry. That means that no matterhow much the cam member 610 is rotated in order to reach the brush 432surface, the cam 610 will contact the brush 432 with the same angle andsame large force to resist sliding of the brush within the brushretainment member 104. Not all brushes may be exactly the same size soit is important that each cam member 610 is free to independently rotateon the shaft 620 to the fill the actual gap between the shaft 620 andthe corresponding brush 432 surface.

FIG. 13 illustrates a simplified side view of the cam 610 in twopositions, according to an aspect of the present invention. When thebrush retainment member 104 is not fully inserted into the stationarysupport 102, the cam 610 will be rotated downward and into contact withbrush 432. Once the brush retainment member 104 is fully inserted intostationary support 102, the cam 610′ (shown in phantom) will be pushedup and away from the brush 432 by rod 240 (shown in phantom).

The spring 612 biases the cam member 610 towards the brush 432. As thebrush 432 travels radially downward, through box 430, the cam member 610contacts the brush 432 (via a wedge action) and prevents furtherdownward movement of the brush 432. In effect, the cam member 610prevents the brush from just falling through the box 430. The cam member610 and spring 612 are configured so that the cam 610 will not damagethe brush 432, and that brush 432 insertion and removal can beaccomplished without the use of tools (i.e., it can be done easily byhand). In use, the brushes 432 are installed in the boxes 430 and thecam members 610 hold the brushes 432 in place. The brush retainmentmember 104 can now be inserted into the stationary support member 102.When the cam members 610 contact bar 240 (which occurs when the brushretainment member 104 is almost fully, if not completely, inserted intostationary support member 102), the cam members are pushed upward (bybar 240) and retract from the brushes 432. This action permits thebrushes 432 to then drop onto the collector ring 120. Conversely, whenthe brush retainment member 104 is unlocked and withdrawn from thestationary support member 102 each cam member 610 will lose contact withthe bar 240 and regain contact with its brush 432. This will ensure thatthe brush 432 loses contact with the collector ring 120 and is withdrawnwith the brush retainment member 104. Additionally, when the brushretainment member 104 is withdrawn from the stationary support 102, thecam members 610 shown and described herein may allow for installationand/or replacement of brushes 432 using a single hand (e.g., oneoperator's hand) without the use of additional brush change tooling.This may provide advantages, for example, safety and efficiencyadvantages, over the conventional systems and approaches.

FIG. 7 illustrates a perspective view of a stationary support member702, according to an aspect of the present invention. The stationarysupport member 702 is an alternative embodiment and includes twoopposing grooves 710 and a fork electrical connector 720. The forkelectrical connector 720 may extend to one or both sides of thestationary support member, or alternatively the fork electricalconnector may only be centrally located without extending to the sidesof the stationary support member (as shown). A tapered slot 730 islocated in an upper portion of the stationary support member 702, andthe slot 730 is configured for cooperation with a locking pin 450 on thebrush retainment member. The upper tapered surface of slot 730 acts toforce the brush retainment member down into the connector 720 as thelocking pin 450 is rotated into the slot. A bar 740 is located near abottom end of the stationary support member 702, and this bar 740 isconfigured to engage and restrain a cam on the brush retainment member104. A plurality of holes 750 are provided and are configured tofacilitate attachment of the stationary support member 702 to thecollector mount (or collector horseshoe 110). The holes 750 may beinternally threaded for use with mechanical fasteners, such as bolts orscrews. In addition, the holes 750 may be provided on both sides of thestationary support member 702 so that they are configured to attach aplurality of stationary support members together in a stacked orside-by-side arrangement. The fork connector 720 is electricallyconnected to the horseshoe 110 through the stationary support member702.

FIGS. 8 and 9 illustrate a schematic view of a plunger brush restraintthat may be used with the brush holder, according to an aspect of thepresent invention. FIG. 8 shows the brush 432 restrained by the plungerbrush restraint and FIG. 9 shows the plunger brush restraint retractedallowing the brush 432 to drop down onto collector ring 120. FIGS. 8 and9 illustrate an alternative way to retain the brush 432 from sliding inthe holder or box 830. The stationary support is illustrated by 802 andthe brush retainment member by 804. Rather than using a rotating cam 610(see FIGS. 5-6), a plunger brush restraint apparatus having a plungerbrush restraint 810 may be used to contact and restrain brush 432. FIG.8 shows the plunger brush restraint 810 configured to restrain brush 432by contacting the brush 432. The plunger brush restraint 810 isconnected to a rotating or pivoting bar 812 and contour follower 813through a pivot support 814. The top of the pivoting bar 812 is pivoted(or biased) away from the brush holder box (or brush retainment member)830 by a plunger spring 816. In this manner spring 816 biases theplunger 810 against the brush 432. In FIG. 8, the spring 816 is in theextended position that corresponds with insertion and removal of thebrush retainment member 804. Note that the contour follower 813 ispassing a section of the contoured surface 803 of the inside wall of thestationary support 802 that is farther from the brush retainment member804 (or brush box 830). As the brush retainment member 804 reaches itsfully inserted position in stationary support 802, shown in FIG. 9, thecontoured surface 803 is closer to the brush box 830 so that the contourfollower 813 is forced closer to the brush box 830. This actioncompresses the spring 816, rotates/pivots the bar 812 about the pivotsupport 814 and retracts the plunger brush restraint 810. In thismanner, the pivoting bar 812 and contour follower 813 are configured tofollow the contoured surface 803 of the stationary support member 802.Once the plunger 810 is retracted (from brush 432), the brush 432 isallowed to slide freely inside the brush box 830 and then drop onto thecollector ring 120. During insertion or removal of the brush retainmentmember 804, the brush 432 is restrained against brush box 830. Once thebrush retainment member 804 is fully inserted into stationary supportmember 802, the plunger 810 is retracted and the brush is releasedallowing it to drop (with the aid of brush spring 834) onto collector120.

FIG. 10 illustrates a perspective view of a brush holder, according toan aspect of the present invention. The brush retainment member 1004includes a wireless RFID (radio frequency identification) tag 1000mounted on (or affixed to) the brush retainment member box 1030.Separate RFID tags 1000 may be used to monitor each brush 1032 in abrush retainment member 1030 or one RFID tag 1000 (as shown in FIG. 10)may be used to monitor a single brush 1032 to give a representativefeedback on the behavior of multiple brushes 1032. The RFID tag 1000 isconfigured to monitor brush 1032 wear and communicate brush wear statusto a monitoring system. The RFID tag 1000 includes a main body 1001 thatis configured for attachment to the brush box 1030. Adhesive (not shown)may be placed between the main body 1001 and the brush box 1030, tosecurely mount the RFID tag in the desired location. Alternatively,magnets or fasteners (e.g., bolts or screws) or hook and loop fastenerscould also be used to attach the RFID tag to the brush holder. The RFIDtag 1000 includes a proximity sensor 1010 configured for detecting thepresence of the brush 1032 located at least partially inside the brushholder 1030. The RFID tag 1000 includes a temperature sensor 1020configured for detecting the temperature of at least one of the brushholder 1030 and an air temperature near the brush holder 1030. Theproximity sensor 1010 is located or positioned in or over viewing window1031.

The RFID tag 1000 is configured to transmit a wireless signal that isrepresentative of, or may be used to determine, remaining life of thebrush 1032 and/or an abnormal operating condition of the brush via anexcessively high or low temperature. The wireless signal istransformable into an indication of a normal or abnormal operatingcondition of the brush, or into an indication of the remaining life ofthe brushes 1032. For example, a brush temperature that is too high ortoo low, may indicate an abnormal operating condition of the brush,whereas a temperature within normal operating parameters may indicate anormal operating condition. A signal from proximity sensor 1010 may betransformable into an indication of the remaining life of the brush1032, and this indication can be a binary type indication or display(e.g., GOOD or REPLACE), or it may have greater specificity (e.g., GOOD(or greater than a minimum amount of time), 5 weeks left, 4 weeks left,3 weeks left, 2 weeks, left, etc.). It is to be understood that timeincrements of various quantities (e.g. years, months, weeks, days,hours, etc.) or specific brush lengths (e.g., mm, cm, etc.) may be usedto determine or indicate the amount of remaining brush life as well.

FIG. 11 illustrates a perspective view of RFID tag 1000, according to anaspect of the present invention. The RFID tag 1000 includes a proximitysensor 1010 on or in the main body 1001. The proximity sensor 1010 isconfigured for detecting the presence and/or position of a brush 1032located inside the brush box 1030. The proximity sensor 1010 may be aninductor coil circuit, an electro-mechanical switch or any othersuitable proximity sensing device. For example, the inductor coilcircuit could be configured to provide a signal representative of aposition of the brush inside the brush holder, as described hereinafter.The main body 1001 may also include a temperature sensor 1020, and thetemperature sensor 1020 is configured for detecting the temperature ofthe brush box 1030 and/or the air temperature near the brush box 1030.The temperature sensor 1020 may be a resistor, resistance temperaturesensor (RTD), thermistor, thermocouple, or any other suitabletemperature sensing device.

The RFID tag 1000 is configured to transmit a wireless signal to aremote location (e.g., one or more antennas), and this wireless signalis representative of a remaining life of the brushes 1032. For example,“representative” is defined as being able to be used for determining thecondition, state and/or position of the brush 1032, in brush box 1030.The condition, state or position may be a PASS (e.g., good) or FAIL(e.g., replace). Alternatively, the position of the top of the brush1032 may be detected (by an inductor coil circuit or anelectro-mechanical switch) as it passes by the proximity sensor 1010,and this changing position may be used to estimate the remaining life ofthe brush in a temporal period (e.g., 2 weeks of life remaining beforereplacement needed). Using multiple proximity sensors 1010 at differentlocations on the RFID tag 1000 corresponding to multiple brush lengthscould be used to identify multiple stages of wear.

The RFID tag 1000 is preferably comprised of low voltage and lowamperage components to reduce current consumption. This enables the RFIDtag 1000 to be either fully passive (in that it receives all of itspower from the interrogating signals sent by the antenna(s) 1230) orthat a battery within each RFID tag 1000 will have a long life. Sincethe RFID tag 1000 does not harvest its energy from the current orvoltage in the brush 1032, the apparatus and system 1200 can be fullyoperational when the dynamoelectric machine is neither energized nor inoperation. The passive or active RFID tag 1000 may be configured to havelow current consumption, and these low current consumption levelsprovide substantially improved results, because wires leading to eachand every brush are no longer required. These results were unexpectedbecause it was not anticipated that such a low power device wouldperform satisfactorily in a dynamoelectric machine environment, howevertesting has proven that accurate and reliable results have been obtainedwith the system and apparatus as herein described.

The RFID tag 1000 may be configured as a radio frequency identification(RFID) device or tag, which can transmit and receive wireless signals toand/or from a receiving antenna. The RFID device may transmit in afrequency range of about 800 MHz to about 1 GHz, or about 2.4 GHz, orany other suitable frequency range. The RFID device may be configured asa passive device and receive its power from an interrogating signal,such as that received from a remotely located or nearby antenna (e.g.,the one or more antennas 1230, as shown in FIG. 12). The RFID device mayalso be configured as an active RFID device that contains its own powersource (e.g., a battery 1050) and it sends it output to the externalantenna 1230, but does not need an interrogating signal, or it may beconfigured as a battery-assist passive RFID device where power isobtained from an internal power source and the interrogating signalcomes from an external source, for example antenna 1230.

The RFID tag 1000 may include a variety of low power circuits anddevices. As only one non-limiting example, the RFID tag 1000 includes aproximity sensor 1010, which may be an inductor coil, a temperaturesensor 1020, an antenna 1025 and an RFID chip 1040. It is to beunderstood that additional or different circuits, components and IC(integrated-circuit) chips could be used to comprise the apparatus aswell.

FIG. 12 illustrates a simplified schematic view of a system in adynamoelectric machine, according to an aspect of the present invention.The system 1200 includes one or more brush holders 1210, each configuredfor holding one or more brushes 1220, and the brush holder 1210 isconfigured for use in a dynamoelectric machine 1205. For example, thedynamoelectric machine may be a generator with a rotating DC field or arotating AC armature, or a motor. An RFID tag 1000 is attached to thebrush holder 1210, and the RFID tag 1000 includes one or more proximitysensors configured for detecting the presence of the brush 1220 locatedat least partially inside the brush holder 1210. The RFID tag 1000 mayalso include a temperature sensor configured for detecting thetemperature of the brush holder 1210 and/or an air temperature near thebrush holder 1210. The RFID tag 1000 is configured to transmit awireless signal to one or more antennas 1230 disposed within or near thedynamoelectric machine 1205, where the one or more antennas 1230 areconfigured to receive the wireless signal from (and in some embodiments,transmit energy to) the RFID tag 1000. The wireless signal isrepresentative of, or may be used for determining, a remaining life ofthe brush 1220. As each RFID tag 1000 may be assigned a uniqueidentification code, it is possible to identify the state or conditionof each brush 1220.

The system 1200 may transmit data to a local or remotely locatedmonitoring station or system 1240. A technician can view the receiveddata (from the wireless signals) and monitor the state or condition ofeach brush in the dynamoelectric machine 1205. The data regarding eachbrush may be displayed in graphical or tabular form, and could betransformed into an indication of the remaining life of each brush orthe amount of time until the brush fails or the amount of time untilreplacement is needed.

The apparatus, brush holder and system are configured to monitor avariety of conditions of the brush and/or brush holder using sensortypes including: temperature, electromagnetic, pressure, strain,acceleration, resistance, electromechanical, magneto resistive, halleffect, current measurement and/or other suitable devices. The apparatusand sensor(s) can be located on (in physical contact with) and/orproximate to, a brush holder, for assessing the general condition of thebrush/commutator apparatus of the dynamoelectric machine. In oneparticular embodiment, brush position and/or temperature measurementsprovide a mechanism for determining whether and when to perform brushreplacement or adjustment.

One advantage provided by the present invention, is that the RFID tag1000 can be added to an existing brush holder, so that the brush itselfdoes not have to be modified. As the brush is a “consumable item, thisprovides an economic advantage to the user, because they can purchase,use and replace standard brushes for low cost. The apparatus and systemherein described also avoids the use of extra wires attached to thebrush holder or brush itself. The “extra wires” approach has potentialfor additional shorting paths and excessively noisy signals from theadjacent energized components. It also interferes with visual inspectionand the brush changing operation. The present invention also providesthe advantage of eliminating sensors physically attached or embeddedwithin the brush. This reduces cost and eliminates the possibility thatthe brush will be adversely affected when sliding along the brushholder, as any attachment onto the brush presents the possibility forthe brush to get stuck in the brush holder. If a brush gets stuck andstops sliding down the brush holder, a gap will form between the brushand collector, and this could lead to undesired arcing and eventualmachine failures. It can also be fully operational when the rest of thedynamoelectric machine is not in operation.

The brush holder, apparatus and system according to the aspects of thepresent invention, may be used with, or applied to, any dynamoelectricmachine. As non-limiting examples only, dynamoelectric machines mayinclude motors and generators with either a rotating dc field or arotating ac armature. The brush holder, apparatus and system of thepresent invention demonstrates substantially improved results, that wereunexpected, because a brush holder is now provided that enablesone-handed insertion and removal without the use of any tools, andinsulates and protects a user's hand from contact with live(electrically energized) brush leads on operating dynamoelectricmachines.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. A brush holder apparatus comprising: a stationary support memberhaving at least one groove, the stationary support member having a forkelectrical connector; a brush retainment member having a brush restraintapparatus, the brush restraint apparatus having a plunger brushrestraint configured to restrain a brush from sliding within the brushretainment member by pressing it against the brush retainment member,the brush retainment member having at least one rail configured to slidealong the at least one groove, the brush retainment member having aknife electrical connector configured to mate with the fork electricalconnector; and wherein the brush retainment member is configured to bereleasably affixed to the stationary support member, and the stationarysupport member is configured for electrical connection to a collectormount and the brush retainment member is configured to retain at leastone brush.
 2. The brush holder apparatus of claim 1, the brush restraintapparatus further comprising: a pivoting bar connected to the plungerbrush restraint, the pivoting bar connected to a pivot support and aspring that biases the plunger brush against the brush, the pivoting baris configured to follow a contoured surface of the stationary supportmember during insertion of the brush retainment member into thestationary support member; and wherein the brush is restrained againstthe brush retainment member during insertion of the brush retainmentmember into the stationary support member, and the brush is releasedwhen the brush retainment member is fully inserted into the stationarysupport member.
 3. The brush holder apparatus of claim 2, wherein thestationary support member further comprises: a tapered slot configuredfor cooperation with a locking pin on the brush retainment member. 4.The brush holder apparatus of claim 2, wherein the stationary supportmember further comprises: a plurality of holes configured to facilitateattachment of the stationary support member to the collector mount. 5.The brush holder apparatus of claim 4, wherein the plurality of holesare configured to attach a plurality of stationary support memberstogether.
 6. The brush holder apparatus of claim 2, wherein thestationary support member further comprises: a conductive spacer platelocated on a side of the stationary support member, the conductivespacer plate configured to provide electrical conductivity with thecollector mount or a second stationary support member.
 7. The brushholder apparatus of claim 2, wherein the fork electrical connector ofthe stationary support member is substantially centrally located in thestationary support member, or wherein the fork electrical connector ofthe stationary support member extends to one side of the stationarysupport member.
 8. The brush holder apparatus of claim 2, wherein atleast one of the stationary support member and the brush retainmentmember is comprised of aluminum or an aluminum alloy.
 9. The brushholder apparatus of claim 2, wherein at least one of the stationarysupport member and the brush retainment member is comprised of apassivated or anodized aluminum or a passivated or anodized aluminumalloy, and wherein at least a portion of a surface of at least one ofthe stationary support member and the brush retainment member isconfigured to be substantially electrically insulating.
 10. The brushholder apparatus of claim 2, wherein at least one of the stationarysupport member and the brush retainment member is comprised of a powdercoated or painted aluminum, a powder coated or painted aluminum alloy, aceramic coated metallic or ceramic coated non-metallic material, andwherein at least a portion of a surface of at least one of thestationary support member and the brush retainment member is configuredto be substantially electrically insulating.
 11. The brush holderapparatus of claim 2, the brush retainment member further comprising: ahandle assembly comprising an electrically insulating handle having anelectrically insulating guard configured to be located between thehandle and brush connector leads.
 12. The brush holder apparatus ofclaim 11, the handle assembly further comprising: a locking pinconfigured for cooperation with a tapered slot in the stationary supportmember, and wherein the handle assembly is configured for rotation sothat the locking pin may be rotated into and out of the tapered slot.13. The brush holder apparatus of claim 12, wherein the handle assemblyis configured to be rotated about 90 degrees, a 0 degree positionconfigured so that the locking pin is disengaged from the tapered slotso that the brush retainment member may be removed from the stationarysupport member, and a 90 degree position configured so that the lockingpin is engaged in the tapered slot so that the brush retainment memberis fully locked into operating condition on the stationary supportmember.
 14. The brush holder apparatus of claim 11, the handle assemblyfurther comprising: a spring assembly mechanically connected to a brushterminal compression plate, the spring assembly configured to applypressure to one or more brush terminals at least until the electricallyinsulating handle is in a locked position.
 15. The brush holderapparatus of claim 2, wherein the brush retainment member is configuredto accept a single brush or a plurality of brushes.
 16. The brush holderapparatus of claim 2, wherein the brush retainment member is configuredto clamp a brush terminal between a terminal compression plate and anopposing surface of the brush retainment member, and wherein the brushterminal is engaged without the use of any tools.
 17. The brush holderapparatus of claim 16, wherein the brush terminal includes at least oneof: a bend, a rib, a hole or a notch, a protrusion; and wherein thebrush retainment member includes a complementary feature to the bend,the rib, the hole, the protrusion or the notch to facilitate securingthe brush terminal to the brush retainment member.
 18. The brush holderapparatus of claim 2, wherein the brush retainment member is configuredto electrically and mechanically connect the knife electrical connectorto a brush terminal; and wherein the knife electrical connector and thebrush terminal are electrically insulated from a handle of the brushretainment member.
 19. The brush holder apparatus of claim 2, the brushretainment member further comprising: a brush spring configured to pressa brush against a collector of a dynamoelectric machine, and wherein thebrush spring is configured to be replaceable in the brush retainmentmember; and wherein the brush spring is configured to be located in-linewith the plunger brush restraint configured for restraining a brushagainst the brush retainment member.